Quantum Institute: Visitor Schedule

The Quantum Lunch is regularly held on Thursdays in the Theoretical Division Conference Room, TA-3, Building 123, Room 121.
For more information, contact Diego Dalvit.

Thursday, May 14, 2009
12:30 PM - 2:00 PM

Speaker: Michael Zwolak, T-4

Title: Quantum Darwinism in a hazy environment

Abstract
Quantum Darwinism recognizes that we - the observers - acquire our information about the "systems of interest'' indirectly from their imprints on the environment. We examine how information about a system can be acquired from a mixed-state, or hazy, environment. We show that the storage capacity for information of a fragment of the environment is suppressed by its initial entropy. In the case of good decoherence, the mutual information between the system and the fragment is given solely by the fragment's entropy increase. For fairly mixed environments, this means a reduction by a factor 1-h, where h is the haziness of the environment, i.e., the initial entropy of an environment qubit. We show that even such hazy environments eventually reveal the state of the system, although now the size of the intercepted environment fragment must be larger by ~1/(1-h) to gain the same information about the system.